1. Field of the Invention
The present invention relates to an assist tool that allows a treatment tool to be easily inserted into a treatment tool insertion channel of an endoscope, and also to a treatment tool for an endoscope that is to be used in the assist tool.
2. Description of the Related Art
Usually, a treatment tool for an endoscope has a flexible shaft that is to be inserted into and extracted from a treatment tool insertion channel of an endoscope. The flexible shaft is forcedly inserted into the channel while being nipped by the fingers of an operator. During this operation, the flexible shaft may be easily bent and broken due to its lack of firmness.
Countermeasures against the above-described problems have been proposed. An adapter for restricting a flexible shaft from being bent, so as to allow the flexible shaft to be pushed only in a straight direction has been proposed in Japanese Utility Model Examined Publication No. SHO56-37683. Additionally, a flexible shaft sandwiched between a pair of rollers that are driven by a motor has been proposed in Japanese Patent Unexamined Publication No. HEI9-492.
However, the aforementioned proposals have not been successful in overcoming the above-described problems. The adapter for restricting the flexible shaft from being bent has drawbacks in that it is difficult to smoothly insert or extract the flexible shaft, and the adapter is hardly used. In the motor-driven configuration, the operator cannot sense the movement of the treatment tool, and hence a dangerous situation may arise.